Liquid cooling system for all-in-one computer

ABSTRACT

A desk-top type computer with a built-in LCD includes a chassis, a planar display attached to the chassis, a mother board attached to the chassis, heat generating portions including a CPU mounted on the mother board, and a memory device electrically connected to the mother board. A heat receiving head is fixed to at least one of the heat generating portions including the CPU, and the head is connected a tube filled with a cooling liquid. The tube is arranged in a serpentine or zigzag shape in a clearance between the chassis and the planar display facing the chassis. The cooling medium liquid circulating in the tube serves as a heat transferring medium to absorb the heat at the heat generating portion, and radiate the heat through the tube disposed in the clearance between the LCD and the chassis.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a desk-top type computerintegrated or combined with a liquid crystal display (LCD), or anall-in-one computer, and more particularly, to a liquid coolingtechnology for a heat generating elements in such a desk-top typecomputer.

[0002] A conventional art concerning a cooling system for electronicequipment is such that a metal plate or heat pipe is interposed betweenheat generating elements and a metal cabinet wall in the electronicequipment to thereby interconnect them thermally, thus radiating theheat generated by the heat generating elements through the metal cabinetwall.

[0003] Japanese Patent Application Laid-Open Publication No. H07-142886discloses a technology for liquid-cooling heat generating elements inelectronic equipment. It describes such a construction that the heatgenerated by semiconductor heat generating elements in the electronicequipment is received by a heat receiving head, a cooling medium liquidin which head is in turn transported through a flexible tube to a heatradiating head provided on a metal cabinet of a display unit to therebyradiate the heat generated by the semiconductor heat generating elementsthrough the heat radiating head via the cooling medium liquid from themetal cabinet effectively. The above-mentioned publication alsodiscloses an example of using a heat pipe as a heat transporting device,which has a construction that the heat generated by the semiconductordevices is transferred through a heat receiving metal plate to the heatpipe and then thermally connected to the other end of the heat pipedirectly attached to the wall surface of a metal cabinet, which servesas a heat radiating surface, to be radiated to the outside.

[0004] Further, Japanese Patent Application Laid-Open Publication No.H11-154036 discloses a heat dissipation technology for a desk-top typecomputer having an LCD unit. This publication specifically describesthat the air entered in a casing through an air inlet hole in a lowercasing section thereof, which surrounds the LCD, a mother board, etc.,is warmed by the heat from the mother board and a power source and thendischarged to the outside through heat radiating holes formed in the topand back surfaces of an upper casing section and in the top surface ofthe lower casing section. The publication further describes that acooling fan is provided at lower portion of the mother board to improvethe cooling efficiency.

[0005] In a desk-top type computer that typically comprises a bodysection having an LCD and a stand portion for rotatably supporting thebody section, heat is generated by a CPU or MPU, etc. (hereinaftergenerally referred to as CPU) built in the body section, and the heatthus generated sometimes makes the operations of circuits unstable. Itmay also cause to thermal deformation of mechanisms. In particular, withan increase in the operating frequency of the CPU in the recent years,the value of heat generated increases, and it has been desired toeffectively radiate the thus increased heat.

[0006] In the conventional art, there were discussions on the cooling bymeans of a cooling medium liquid and that using a heat pipe for generalelectronic equipment. Concerning the cooling technologies for a desk-toptype computer integrated with an LCD, however, only some air coolingtechnologies have been suggested as is in Japanese Patent ApplicationLaid-Open Publication No. H11-154036. There have been no technologiesdisclosed presently of a cooling construction that is suited for thedesk-top type computer wit the built-in LCD.

[0007] It is conceivable to cope with an increase in the value of heatgenerated in the desk-top type computer by increasing the ventilationcapacity of a fan. This measure, however, may give rise to a problem ofnoise due to the blowing sound of the fan and another problem ofvibration during the operation of the computer. It is also conceivableto increase the heat radiation capacity by enlarging the size of an aircooling heat sink or heat radiating plate for radiating the heatgenerated by the heat generating elements such as a CPU. Thiscountermeasure is contradictory to the requirement for downsizing orminiaturization of the desk-top computer.

SUMMARY OF THE INVENTION

[0008] It is an object of the invention to provide a cooling technology,which is useful to be applied a desk-top type computer with an LCD unit,and to propose a novel construction for obtaining an appropriate heatradiating effect that is impossible with the prior art.

[0009] A display unit integral type computer, or an all-in-one computer,comprises a chassis, a plane-shaped display attached to the chassis, amother board attached to the chassis, a variety of electronic devicesand a CPU mounted on the mother board, and a memory device electricallyconnected to the mother board. A heat receiving head is fixed to atleast one heat generating portion including the CPU. A tube filled witha cooling medium liquid is connected to the heat receiving head, and thetube is secured onto the surface of the chassis, which is disposedopposite to the plane-shaped display with a clearance therefrom. Thecooling medium liquid circulating through the tube serves as a heattransferring medium to radiate the heat generated at the heat generatingportion through the tube on the chassis surface and the chassis itself.

[0010] Alternatively, the tube may be secured onto the back surface ofthe plane-shaped display, which is opposite to the chassis and attachedthereto with the clearance therefrom. The cooling medium liquidcirculating through the tube serves as a heat transferring medium, thusradiating the heat generated at the heat generating portion through thetube secured to the back surface of the plane-shaped display and theplane-shaped display itself.

[0011] Further alternatively, the tube may be led through the clearancebetween the back surface of the plane-shaped display and the surface ofthe chassis and secured onto the back surface of the plane-shapeddisplay and onto the chassis surface. The cooling medium liquidcirculating through the tube serves as a heat transferring medium, thusradiating the heat generated at the heat generating portion through thetube on the back surface of the plane-shaped display and the chassissurface, the chassis, and the plane-shaped display.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1 is a section view showing an overall configuration forliquid cooling of a desktop type computer according to an embodiment ofthe invention;

[0013]FIG. 2 is a front view of the overall configuration of FIG. 1 inwhich a tube and a liquid receiver are fixed onto a main chassis;

[0014]FIG. 3 is a rear view of the overall configuration of FIG. 1 inwhich an assembly of a CPU and a heat receiving head, and a pump aredisposed on a mother board;

[0015]FIG. 4 is a section view of another embodiment of the invention,in which a tube is secured to an LCD panel for heat radiation;

[0016]FIG. 5 is a section view showing a configuration example forpreventing leakage of a cooling liquid in a desk-top type computeraccording to still another embodiment of the invention;

[0017]FIGS. 6A and 6B are views illustrating configuration examples forliquid cooling and air cooling of a CPU according to the embodiment ofthe invention;

[0018]FIGS. 7A, 7B, and 7C are views showing configuration examplesconcerning the layout of a tube for liquid cooling in embodiments of theinvention;

[0019]FIG. 8 is a section view showing another configuration exampleconcerning the layout of a tube for liquid cooling in an embodiment ofthe invention;

[0020]FIGS. 9A and 9B are section views showing configuration examplesconcerning the layout of a tube, a main chassis, and an LCD for liquidcooling according to embodiments of the invention;

[0021]FIG. 10 is a section view showing a configuration for liquidcooling according to an embodiment of the invention, in which fansexhaust heat;

[0022]FIGS. 11A, 11B and 11C are schematic diagrams showing the layoutof a pump, a heat receiving head, a tube and a liquid flowing direction;

[0023]FIG. 12 is a schematic diagram showing the function of a reservoirtank for supplementing a cooling medium liquid and a function ofremoving air bubbles at the tube, heat radiation portion for liquidcooling according to the embodiment of the invention;

[0024]FIG. 13 is a section view of a configuration example for liquidcooling according to an embodiment of the invention, in which a tube anda liquid receiver are disposed on a rear cover; and

[0025]FIG. 14 is a section view of a configuration example for liquidcooling according to an embodiment of the invention, in which a tube isdisposed on a main chassis facing a rear cover.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026]FIG. 1 shows an overall configuration for liquid cooling of adesk-top type computer according to an embodiment of the invention, FIG.2 is a front view of the overall configuration of FIG. 1 in which a tubeand a liquid receiver are fixed to a main chassis, and FIG. 3 is a rearview of the overall configuration of FIG. 1, in which an assembly of aCPU and a heat receiving head, and a pump are disposed on a motherboard.

[0027] As shown in FIGS. 1-3, the desk-top type computer comprises acomputer body 1 and a stand 2 for rotatably supporting the body 1, andin the computer body 1, a liquid crystal display (LCD) panel 5 ismounted on the front side of a main chassis 3 and the mother board (acontrol circuit board) 4 is disposed on the back side thereof.

[0028] On the mother board 4 are arranged a variety ofelectric/electronic devices, ICs, electronic circuits, etc. necessaryfor the operations of the computer as well as the CPU 9, power sourcecircuits, and other elements generating heat during the operation of thecomputer. On the back side of the LCD panel 5, i.e. on its side facingthe main chassis 3 are arranged a large number of connectors, andelectric wiring lines, connected to the connectors, extend through anopening in the main chassis 3 and are connected to terminals of themother board 4. Thus, a space is formed between the main chassis 3 andthe LCD panel 5 for routing the electric wiring lines etc.

[0029] Referring to FIG. 3, on the back side of the mother board, whichis opposite to the main chassis side thereof, are arranged the CPU 9,the power source circuits, a hard disk drive (HDD) 10, etc, whichgenerate heat, and a heat receiving head 8 (see FIG. 1) is provided incontact with the heat generating elements for transferring their heat toa cooling medium liquid. Incidentally, the heat generating sources inthe desk-top type computer include, besides the CPU, a chip set, adisplay controller, a power source portion, an HDD, an FDD, a CD-ROMportion, a CDR-R/W portion, and a DVD-ROM portion. The heat receivinghead 8 is made of a metal material having a high heat transfer rate andhas its interior filled with a cooling medium liquid, which is thermallytransported to a heat radiating portion distanced from the heatreceiving head. Used as the cooling medium liquid is water or ethyleneglycol, but it is not limited to them. The cooling medium liquid ispressured by a pump 7 shown in the figure to collect heat at the heatreceiving head 8 while it is being circulated through a tube 6.

[0030] Although the tube 6 for transporting the cooling medium liquid istypically made of copper with a good heat transfer rate and a corrosionresistance, any other material may be used as far as they have theabove-mentioned properties. For example, a flexible tube made of asilicon-based compound can be employed because it has those properties.As will be described later, in particular such a tube as shown in FIGS.13 and 14 is routed in the same manner as a cable, and therefore aflexible tube may be used as a portion other than those fixed to thecover or the chassis. For instance, part of the path requiringflexibility may be made by a flexible tube of silicon-based compound inplace of a copper tube.

[0031] The tube 6 for transporting the cooling medium liquid goesthrough the heat receiving head 8, the pump 7, and the opening in themain chassis up to the front side of the main chassis (see FIG. 2), i.e.up to the space between the main chassis 3 and the LCD panel 5, and isfixed to the main chassis front side by screwing, bury-in, or any otherappropriate fixing method, thus forming a heat radiating portion. It isto be noted here that the place where the tube is disposed on the frontside of the main chassis is the space originally provided for, asdescribed above, arranging the electric wiring lines etc. of the LCDpanel, that is, it utilizes the existing space and is not a newly addedspace for arranging the tube piping on the front side of the mainchassis 3. Thus, this is not adverse to the requirement for thinning andminiaturization of the entire equipment.

[0032] As shown in FIG. 2, the tube 6 is secured on the front side ofthe main chassis, while being arranged spirally or in a zigzag orserpentine manner. With this construction, the heat generated by the CPUetc. and transferred to the cooling medium liquid is effectivelytransferred to the main chassis 3 through the copper tube. The mainchassis is originally for forming an overall computer framework that iscoupled with the stand 2, and it has a considerably large area in totaland is made of a metal material. Accordingly, all the area of the frontand rear sides of the chassis can be used for external heat radiation,thus achieving a high efficiency heat radiation.

[0033] Referring to FIG. 2 again, the tube 6 fixed, for example,spirally, on the front surface of the main chassis 3 has a possibilitythat the cooling medium liquid will leak at the joints of its flexion orbending portions due to thermal shrinkage thereof. To prevent the thusleaked cooling medium liquid from flowing along the main chassis down tothe stand, a liquid receiver 11 for collecting that cooling mediumliquid is provided at the lower part on the front side of the mainchassis. The main chassis is usually kept in an upright state or a stateslightly inclined with respect to the upright state, and the leakedliquid flows downward along the surface of the main chassis and can becollected in the liquid receiver 11. Although FIG. 2 shows the examplewhere the liquid receiver 11 is disposed on the front surface side ofthe main chassis 3, another liquid receiver may be provided on the backside to collect the leakage liquid coming down along the tube.

[0034] Further, a cover 12 is provided for covering the whole of thecomputer body 1. A portion of the cover 12 that corresponds to the lowerportion of the space between the LCD panel 5 and the main chassis 3 isformed with an air inlet 13 for air-cooling the heat radiating portionthat comprises the heat transporting tube and the main chassis.Similarly, the upper portion of the cover 12 is also formed with an airoutlet 14 for exhausting air. An air flow-through path from the airinlet 13 to the air outlet 14 has a chimney effect for air to effect afurther air-cooling on the heat generating portion, thus improving thecooling efficiency.

[0035] In a modification of the first embodiment of the inventiondescribed above, an air ventilating fan is provided at the lower portionin the cover to forcedly take in air for heat exchange at the heatgenerating portion and then exhaust the air, thus further improving thecooling efficiency.

[0036] As mentioned above, according to the first embodiment of theinvention, the casing (or cover) of a currently used desk-top typecomputer can be used as it is without changing its size. Further, alarge surface area of both the front and back sides of the main chassiscan be utilized in radiation of heat to achieve an even more improvedheat radiation effect. Furthermore, the chimney effect of air at theheat radiating portion of the tube is expected to further improve theheat radiation effect.

[0037]FIG. 4 now shows a configuration example for liquid cooling of adesk-top type computer according to another embodiment of the invention.As shown in FIG. 4, this embodiment is so constructed that a tube goesthrough a pump, a heat receiving head, and an opening in a main chassisand is fixed on the back surface of an LCD panel to form a heatradiating portion. The back surface of the LCD panel is made of a metalmaterial, and the heat of a cooling medium liquid from the tube, whichis arranged spirally or in a zigzag or serpentine manner, can betransferred effectively onto the back surface of the LCD panel andradiated.

[0038] A space between the LCD panel and the main chassis is utilizedfor arranging electric wiring lines etc., which are connected with theconnectors of the LCD panel in the same manner as described with theembodiment shown in FIG. 1. Accordingly, no additional space is requiredfor arranging the tube on the back surface of the LCD panel to form theheat radiating portion. Also in the embodiment shown in FIG. 4, the heatradiating portion can be provided without changing the externaldimensions of the currently-used casing of a desk-top type computer,thus contributing the thinning and miniaturization of the computer.

[0039] Furthermore, the back side of the LCD panel has a large area ofthe metal surface, and heat dissipation can be carried out at highefficiency while utilizing this large area. In addition, the provisionof the air inlet in the lower portion of and the air outlet in the upperportion of the cover, which covers the clearance between the LCD paneland the main chassis, form in combination an air flow-through path fromthe air inlet at the lower part to the air outlet at the upper portion,and an improvement of the heat radiating effect is expected due to theso-called chimney effect.

[0040]FIG. 10 shows a modification of the air flowing to the heatradiating portion in the embodiment of FIG. 1, in which an airventilating fan is provided at the lower portion or the upper portion ofthe cover, which covers the clearance between the LCD panel and the mainchassis, or fans are provided at both the upper and the lower portion ofthe cover, respectively. The provision of the fans shown in FIG. 10 canfurther expedite the movement of air. Further, the provision of the fansenables the transportation of a large volume of cooling air. This allowsthe air inlet and outlet openings in the lower and upper portions to benarrowed, thus causing an effect of thinning the apparatus andsuppressing the entry of dust and dirt.

[0041]FIG. 5 now shows a configuration for prevention of liquid leakagein the liquid cooling of a desktop type computer according to anembodiment of the invention. This embodiment takes a countermeasure fora case where cooling medium liquid leaks at a heat radiating portion insuch an arrangement that the heat from a heat receiving head is radiatedon the front side of a main chassis as described with the embodimentshown in FIG. 1. In the desk-top type computer with an LCD, whichcomprises a computer body and a stand, the body is supported by thestand in an upright state or a state slightly inclined from the uprightstate both in use and not in use, so that the liquid leaking from theheat radiating portion, which relatively tends to cause liquid leakagein the liquid cooling apparatus, flows down to the lowest portion of themain chassis because of the above-mentioned inclination state of thecomputer body. Accordingly, this embodiment features providing a liquidreceiver at the lowest portion of the main chassis.

[0042] As can be seen from FIG. 5, the liquid leaking from the heatradiating portion flows downward along the front side surface of themain chassis and is collected by the liquid receiver at the lowestportion of the main chassis. The liquid receiver may be removablyattached at the lowest portion of the main chassis in FIG. 5, or it maybe formed in one united body with the main chassis. Furthermore, in theconfiguration example shown in FIG. 5, the liquid receiver is integratedwith the cover for collecting the liquid coming downward along thesurface of the main chassis.

[0043] Furthermore, as the connections or coupling portions of thecooling medium liquid tube are supported to be liable to cause liquidleakage, a liquid receiver may be provided on the back side of the mainchassis to receive the liquid leaking from the heat receiving head andthe pump. This is because the liquid leaking from that connectingportions of the tube will flow down along the external surface of thetube downward and the back side surface of the main chassis. Inaddition, to receive the liquid dropping from the lowest portion of themother board on which the pump or the heat receiving head is mounted, aliquid receiver may be integrated with the cover at a positioncorresponding to the lowest portion of the mother board. Further, aliquid receiver may be provided on a portion of the stand close to thecomputer body.

[0044] As described above, the embodiments shown in FIGS. 1 and 5 cancollect the leaked cooling medium liquid and also prevent it fromdamaging the devices within the stand.

[0045]FIGS. 6A, B now show configurations for liquid cooling and aircooling in a desk-top type computer according to another embodiment ofthe invention. The embodiment concerning the configurations shown inFIGS. 6A, B has such a construction that a heat receiving head is fixedto a CPU arranged on a mother board to thereby receive the heatgenerated by the CPU in order to transfer the generated heat via acooling medium liquid (water or ethylene glycol) in a tube to a heatradiating portion on the front side of a main chassis or the back sideof an LCD panel similarly to the embodiment shown in FIGS. 1 and 4 andthat a heat radiating fin is provided on the heat receiving head.

[0046] More specifically, the embodiment shown in FIG. 6 aims atradiating by liquid cooling an extra heat that cannot be radiated fromthe heat radiating fin provided on the heat receiving head. Since thedesk-top type computer has an extra space between the back side of themother board and the rear cover, such a heat radiating fin as providedin this embodiment does not lead to an extra change in the externalsizes. FIG. 6B shows a construction in which a fan is further providedon the heat radiating fin on the heat receiving head. The provision ofthe ventilating fan realizes the effective and rapid radiation of heatfrom the heat radiating fin.

[0047] As mentioned above, the embodiment shown in FIG. 6 applies liquidcooling and air cooling in combination to the heat generating sourcesuch as the CPU, and it is possible to increase the maximum capacity ofheat radiation and improve the heat radiation efficiency. Furthermore,the embodiment has an advantage that, even when an abnormal situation inthe liquid cooling system such as freezing of the cooling medium liquidsuch as water, the air cooling effect by the heat radiating fin securedto the heat receiving head allows the computer to be operatedcontinuously.

[0048]FIGS. 7, 8 and 9 show configuration examples concerning the shapeand construction of a heat radiating portion in a tube. FIG. 7A is asection view of the configuration in which a spiral tube for heatradiation is disposed between an LCD panel and a main chassis, FIG. 7Bis a plan view of the configuration of FIG. 7A as viewed from above, andFIG. 7C is a section view of the other configuration, in which a spiraltube is disposed between an LCD panel and a main chassis and a pipe madeof aluminum etc. is disposed at the center of the tube for heatradiation. The examples shown in FIG. 7 employ such a construction thatthe tube, extending from a heat receiving head through an opening in amain chassis, is led to the back side of the LCD panel and arrangedalong this back side, and is then led to the main chassis side andarranged along the surface of the main chassis (the arranging order maybe reversed), thus forming the heat radiating portion. In thisconstruction, both the LCD panel and the main chassis can serve as heatradiating surfaces, and further improvement of the heat radiationefficiency can be expected. The construction shown in FIG. 7C aims atfurther improving the heat radiation efficiency by arranging orattaching the heat radiating metal of aluminum etc. in the central spaceof the spiral tube disposed over the LCD panel and the main chassis.

[0049]FIG. 8 shows a configuration example that a spiral tube isarranged between a mother board, on which heat generating elements aremounted, and a rear cover and, in the central space surrounded by thisspiral tube, a barrel-shaped heat radiating metal such as aluminum isarranged for heat radiation. In the examples of FIG. 8, openings for airventilation are formed as an air inlet and an air outlet in portions ofthe cover corresponding to the upper and lower portions of thebarrel-shaped metal. Then, with a hollow structure of this barrel-shapedmetal, an air path is formed which extends from the air inlet throughthe interior of the hollow body to the air outlet, and the heattransferred from the tube to the barrel-shaped metal is effectivelyradiated thanks to the chimney effect.

[0050]FIG. 9A is a view of the example in which a tube is arrangedbetween an LCD panel and a main chassis with no contact and no fixationthereto, and FIG. 9B is a view showing a distance between an LCD paneland a main chassis, which is almost equal to the diameter of a tube, andthe tube contacting over its entire length with the LCD panel and themain chassis for heat radiation.

[0051]FIG. 11 shows the relationship between a flow direction of acooling medium liquid and a heat radiating system, which comprises apump for supplying the cooling medium liquid, a heat receiving head (awater jacket W/J), a tube, and a tube heat-radiating portion formed in aspiral shape or in a zigzag or serpentine shape. In FIG. 11A, the liquidflows in the direction illustrated, and the flow path from the pumpthrough the heat radiating portion up to the top portion is long.Accordingly, although the pump capacity has to be enlarged by that much,air bubbles, which will occur in the cooling medium liquid in the tubeincluding the heat radiating portion, escape upward along the flow, thusenhancing the effect of removing air bubbles. To this end, an air-bubbleremoving opening is provided at the top portion. In FIG. 11B, since theliquid flows in the direction illustrated, the flow path from the pumpto the top portion is short as compared with that of FIG. 11A, and thepump can be reduced in capacity. Further, FIG. 11C shows the situationthat, since there are a plurality of heat generating elements besidesthe CPU as heat generating sources in the desk-top type computer asdescribed above, a plurality of heat receiving heads providedcorresponding to the plurality of heat generating elements are thermallyconnected in series through the tube.

[0052]FIG. 12 is a schematic diagram showing the function of a reservoirtank for supplementing the cooling medium liquid and the function ofremoving air bubbles in the tube heat radiating portion. As shown inFIG. 12, the reservoir tank for the liquid is provided at the highestportion in the circulating path of the cooling medium liquid, i.e., thetop of the spiral tube structure or the heat radiating portion, and theliquid in the reservoir tank serves as a supplementary liquid when thecooling liquid leaks from the tube or is evaporated. In addition, thedisposition of the reservoir tank at the highest portion of the liquidcirculating path causes air bubbles generated in the circulating path tomove into the above-mentioned tank.

[0053]FIG. 12 also shows the tube heat radiating portion having such ashape that the tube is folded not to simply extend horizontally but in amanner that it goes from one turning point along a path with aninclination angle of a to another turning point. The liquid circulatingpath is thus inclined at the heat radiating portion to cause air bubblesgenerated in the cooling medium liquid at the heat radiating portion toeasily escape into the reservoir tank. That is, this makes it possibleto rapidly eliminate through the reservoir tank air bubbles in thecooling medium liquid, which would occur due to some liquid leakage.

[0054]FIG. 13 now shows another configuration example for liquid coolingin a desk-top type computer according to an embodiment of the invention.In this embodiment, the heat radiating portion of a cooling mediumliquid tube is formed on a back cover or rear cover provided on the backside of a body, and the back cover is typically made of metal orplastic, so that heat may be radiated to the outside from the heatradiating portion through the back cover of a large surface area. Theplastic material of the back cover has almost the same heat radiationproperties as those of metal. FIG. 13 also shows a construction that aliquid receiver for collecting a leakage liquid of the cooling medium isprovided under the tube heat radiating portion disposed on the backcover.

[0055] For maintenance and inspection of the computer which is donetypically by removing the back cover to inspect a variety of deviceswithin the body, this embodiment employs a hinge construction by whichthe back cover can be opened and closed rather than being removed.Alternatively, a construction may be such that the heat radiatingportion is provided on the back cover fixed to the body, and whenmaintenance and inspection, an LCD panel is pushed down forward with itsbottom side as a rotary supporting point and then opened with its sideas a rotary supporting point for inspection of the internal devices.

[0056]FIG. 14 shows further another configuration example for liquidcooling in a desk-top type computer according to an embodiment of theinvention. In this embodiment, as viewed from the front side of thecomputer, an LCD panel, a mother board, a main chassis, a heat radiatingportion, and a back cover are arranged in this order. It has aconstruction that the back cover can be detached from the body, the mainchassis is disposed opposite to the back cover, and the heat radiatingportion is attached to the main chassis, in which heat is transferred tothe back cover through a heat conductor having an elasticity function,which is provided between the heat radiating portion and the back cover.That is, through the elastic heat conductor, the heat radiating portionbutts against the back cover with no gap, thus providing a good heatradiating effect.

[0057] This embodiment enables heat to be radiated through the backcover of a large heat radiation area and an error in mounting of theback cover to be accommodated by means of the elastic heat conductor.

[0058] According to the invention, it is possible to effectively radiateto the outside the heat generated by hot heat generating elements suchas a CPU in a desk-top type computer comprising an LCD.

1. An all-in-one personal computer comprising: at least one heatgenerating portion including a CPU; a display vertically attached toface a chassis with a clearance therefrom; cooling liquid circulatingmeans comprising a tubular flow path filled with a cooling liquid; acooling liquid pump connected with the cooling liquid circulating meansfor circulating the cooling liquid in one direction; heat absorbingmeans, connected to a middle portion of the cooling liquid circulatingmeans for cooling the heat generating portion by means of the coolingliquid; and part of the cooling liquid circulating means being disposedin the clearance between the display and the chassis, so that thecooling liquid circulating in the cooling liquid circulating meansserves as a heat transferring medium to absorb heat generated at theheat generating portion through the heat absorbing means and radiate theheat through at least part of the cooling liquid circulating means. 2.The computer according to claim 1, wherein the cooling liquidcirculating means disposed in the clearance between the display and thechassis is fixed to a surface of the chassis in a heat conduction mannerto radiate the heat generated at the heat generating portion through thecooling liquid circulating means and the chassis.
 3. The computeraccording to claim 1, wherein the cooling liquid circulating meansdisposed in the clearance between the display and the chassis is fixedto a back surface of the display in a heat conduction manner to radiatethe heat generated at the heat generating portion through the coolingliquid circulating portion and the display.
 4. The computer according toclaim 1, wherein the cooling liquid circulating means disposed in theclearance between the display and the chassis is fixed to the chassisand a back surface of the display to radiate the heat generated at theheat generating portion through the cooling liquid circulating means,the display, and the chassis.
 5. The computer according to claim 1,wherein the part of the cooling liquid circulating means is arranged ina serpentine or zigzag shape in a vertical plane facing the display. 6.The computer according to claim 1, wherein the cooling liquidcirculating means disposed in the clearance between the display and thechassis comprises at a vertically highest portion thereof a reservoirtank for the cooling liquid.
 7. The computer according to claim 6,wherein: the part of the cooling liquid circulating means is arranged ina serpentine or zigzag shape in vertical plane facing the display; andthe heat absorbing means is disposed between a cooling liquid outletside of the cooling liquid pump and the reservoir tank, on a downstreamside of which is arranged the part of the cooling liquid circulatingmeans in the serpentine or zigzag shape.
 8. The computer according toclaim 7, wherein the flow path of the cooling liquid circulating meansin the serpentine or zigzag shape has a flow direction inclined upwardwith respect to a horizontal line.
 9. The computer according to claim 5,wherein openings, through which air can enter and exit, are formed in acase at an upper or lower portion of the cooling liquid circulatingmeans disposed in the clearance between the display and the chassis. 10.The computer according to claim 9, wherein at least one of the openingsis provided with a fan.
 11. The computer according to claim 1, whereinthe heat generating portion is heat-conductively fixed to one surface ofthe heat absorbing means, and a fan for cooling the heat absorbing meansis heat-conductively fixed to another surface thereof.
 12. The computeraccording to claim 1, wherein the heat absorbing means is disposed on acooling liquid outlet side of the cooling liquid pump, and part of thecooling liquid circulating means downstream of the heat absorbing meansis disposed in the clearance between the display and the chassis. 13.The computer according to claim 1, wherein the cooling liquidcirculating in the cooling liquid circulating means is discharged fromthe cooling liquid pump, then absorbs the heat generated at the heatgenerating portion through the heat absorbing means, radiates the heatthrough the part of the cooling liquid circulating means disposed in theclearance between the display and the chassis, and then is absorbed bythe cooling liquid pump.
 14. An all-in-one personal computer comprising:at least one heat generating portion including a CPU; a displayvertically attached to face a chassis with a clearance therefrom;cooling liquid circulating means comprising a tubular flow path filledwith a cooling liquid; a cooling liquid pump connected with the coolingliquid circulating means for circulating the cooling liquid in onedirection; heat absorbing means connected to a middle portion of thecooling liquid circulating means for cooling the heat generating portionby means of the cooling liquid; and part of the cooling liquidcirculating means being arranged spirally in a vertical direction, sothat the cooling liquid circulating in the cooling liquid circulatingmeans serves as a heat conducting medium to absorb through the heatabsorbing means, heat generated at the heat generating portion andradiate the heat through at least the cooling liquid circulating meansarranged spirally.
 15. The computer according to claim 14, wherein thecooling liquid circulates, in the cooling liquid circulating meansdisposed spirally in the vertical direction, from a lower portionthereof to an upper portion thereof.
 16. The computer according to claim14, further comprising a hollow pipe arranged vertically, through whichair can flow, wherein part of the cooling liquid circulating means isspirally fixed on an outer periphery of the hollow pipe in a heatconduction manner.
 17. An all-in-one personal computer comprising: atleast one heat generating portion including a CPU; a display attached ina vertical direction of the personal computer; cooling liquidcirculating means comprising a tubular flow path filled with a coolingliquid; a cooling liquid pump connected with the cooling liquidcirculating means for circulating the cooling liquid in one direction;heat absorbing means connected to a middle portion of the cooling liquidcirculating means for cooling the heat generating portion by means ofthe cooling liquid; and part of the cooling liquid circulating meansbeing disposed in a vertical plane facing the display, so that thecooling liquid circulating in the cooling liquid circulating meansserves as a heat transferring medium to absorb, through the heatabsorbing means, heat generated at the heat generating portion andradiate the heat through at least part of the cooling liquid circulatingmeans disposed in the vertical plane.
 18. The computer according toclaim 17, further comprising a back cover which has a vertical surfacefacing the display and is pivotally attached to a rear side of thepersonal computer, wherein part of the cooling liquid circulating meansis fixed to a back surface of the back cover to radiate the heatgenerated at the heat generating portion through the cooling liquidcirculating means and the back cover.
 19. The computer according toclaim 17, further comprising: a back cover which has a vertical surfacefacing the display and is detachably attached to the chassis on a rearside of the personal computer; and a heat conducting member forthermally inter-connecting the back cover and the chassis oppositethereto, wherein part of the cooling liquid circulating means is fixedto the chassis facing the back cover to radiate the heat generated atthe heat generating portion through the cooling liquid circulatingmeans, the heat conducting member, and the back cover.
 20. An all-in-onepersonal computer comprising: at least one heat generating portionincluding a CPU; a display perpendicularly attached in a verticaldirection of the personal computer; cooling liquid circulating meanscomprising a tubular flow path filled with a cooling liquid; a coolingliquid pump connected with the cooling liquid circulating means forcirculating the cooling liquid in one direction; heat absorbing meansconnected to a middle portion of the cooling liquid circulating meansfor cooling the heat generating portion by means of the cooling liquid;and a liquid receiver provided below the cooling liquid circulatingmeans disposed in the vertical plane facing the display, for collectingthe cooling liquid leaking from the cooling liquid circulating means.